Digital communication and smart
instrumentation increases plant efficiency
With many digital communication options now available, modern
instrumentation solutions provide diagnostic information beyond basic process
data, empowering informed decision-making and proactive maintenance.
By Fabrício de Andrade, Endress+Hauser

For decades, control system instrument data wasconstrained to single analog process variables
communicated via individual 4-20mA current loops.
Modern instrumentation advances, particularly digitalcommunications, now provide a wealth of additional
diagnostic and other information, enabling operational
insights unachievable with simple 4-20mA measurements
alone. This extended data helps plant personnel improve
operational efficiency and avoid unplanned shutdowns byempowering them to implement proactive maintenance,and by simplifying calibration procedures.
Modern device-level network media options — like HART®
over 4-20mA, WirelessHART®, Ethernet-APL® andBluetooth® — provide the ability to transmit data bidirectionally between an instrument and its host system.
Various communication methods are selected based on thetarget field devices, depending on the intended application.
For wired installations, plants can implement a combinationof HART over 4-20mA and Ethernet-APL, enabling them toupdate legacy installations and take advantage of newer
fully-digital technology, depending on project needs. For
instruments in hard-to-reach and hazardous locations,
WirelessHART and Bluetooth options enable wirelesstransmission of multiple process variables and diagnostic
data to a wide variety of host systems, providing even more
flexibility for handling instrument data.
Traditional instrumentation challenges
There are many factors impacting and even interfering withthe accuracy of a traditional instrument’s analog output.
Operators interpreting such a signal processed by aprogrammable logic controller, distributed control system,
asset management system, or other host system simply
have no other information regarding the accuracy. Eachanalog loop scales a single process value as electricalcurrent, unable to transmit secondary variables such astemperature on a pressure instrument. Additionally,
communication is unidirectional only, so there is no way tosend commands from a host to the instrument.
Traditional analog instrumentation also lacks diagnostic
information, making it nearly impossible to foresee or
troubleshoot instrument failure. Malfunctions cause
unplanned downtime and costly instrumentation repairs inthe best cases, or catastrophic equipment damage andsafety hazards in the worst. Bound by analog electronics,
traditional instruments must be hardwired to a host system,
limiting placement in hard-to-reach areas of a facility, andespecially in offsite remote locations.
Digital pathways for enhanced connectivity
Digital communication methods increase data availability,
and they provide flexibility for processing the data so plant
personnel can make informed operational and maintenancedecisions. Plant designs featuring smart instrumentation
using digital protocols make facility operation andoptimization much more manageable. We will examinefour modern protocols and transport media that increase
instrumentation value and control system capabilities.
HART over 4-20mA
For retrofitted and new applications where hardwiringtransmitters back to a host system is existing or convenient,
instruments can use the bi-directional digital HART
communication protocol, which is superimposed on a
4-20mA analog current loop, to enable sending andreceiving data between an instrument communicator and ahost system. The exchanged data includes primary process
values, one or more secondary process values, diagnostics,calibration, maintenance, and other information. This

wealth of data makes configuration easy, and it improves
operational process insights, compared to traditional
analog-only instrumentation.
Because HART-enabled instruments can transmit multiple
process values to a controller via a single loop, users gain
flexibility to continue using existing analog loops for real-time
control, while taking advantage of additional process anddiagnostic data to the host system for making data-driven
decisions within a facility.
WirelessHART and Bluetooth
Where wired implementations are impossible orinconvenient, wireless smart instruments provide solutions
via 2.4 GHz radio wave technologies and protocols, notably
WirelessHART and Bluetooth. Many smart instruments
provide these connectivity options natively, while adapters
can be added to provide this functionality for those that donot (Figure 1). These capabilities can be used to create amesh network of sensors around a plant and in the field.
WirelessHART and Bluetooth instruments typically send andreceive as much or more diagnostic and process data as theirwired HART counterparts. While this data can provide
immense benefits to a wide range of host systems andapplications — such as maintenance management, asset
information and health management, inventory control, andenterprise resource planning systems — many facilities do not
yet take full advantage of what this data has to offer.

Figure 1: Endress+Hauser’s SWA50 WirelessHART/Bluetoothcommunication adapter enables any HART-compatible instrument tocommunicate wirelessly.

Ethernet-APLA more recent development is the Ethernet-APL physicaltransport layer, which provides the ability to transmit digital
data via industrial Ethernet protocols using a single twowired shielded cable per instrument. With the same cablerequirements as HART — though markedly different gateway
and termination specifications — Ethernet-APL can simplify
retrofits by eliminating the need to pull new wires toinstruments (Figure 2).
The Ethernet-APL physical layer is protocol agnostic, andsupports industrial protocols such as PROFINET®, EtherNet/IP™,Modbus® TCP, HART-IP, OPC® UA, and other higher-levelnetwork protocols (Figure 3).

Figure 2: Ethernet-APL architecture is highly customizable, requiring only a gateway and power supply to enable data transfer among a wide
range of instruments and various host systems using a single two-wire shielded cable per instrument. In many cases, cables are already present inplants with existing analog instrumentation.
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Figure 3: As a foundational transport layer, Ethernet-APL is capable of carrying any industrial Ethernet protocol. Endress+Hauser Ethernet-APL
instrumentation currently supports PROFINET traffic, with plans to carry EtherNet/IP, Modbus TCP, and additional protocols in the near future.

Ethernet-APL provides high-speed data transmission at a
10Mbit/s data rate, making it possible to send and receive
more data than is possible with older digital methods,
providing a robust basis for continuous diagnostics,
monitoring, industrial internet of things (IIoT) connectivity,
and remote instrumentation verification.

Data can also be analyzed to provide advance warning ofinstrument failure, or troubleshooting insight in the event offailure. Additionally, tracking and managing assets becomeseasier throughout plant lifecycles because calibration andnameplate information for many modern smart instruments
is also recorded.

Because communication is handled via standard Ethernet
protocols, instrument data routing among process control
systems and asset management tools is highly efficient inmodern control environments already using these protocols.

Cloud-based add-ons
Plant managers can extend digital instrument insights evenfurther by leveraging cloud connectivity and computing for
performing advanced analysis, data storage, archival, andretrieval. For example, Endress+Hauser’s Netilion Healthmonitoring service provides insights for past and present
conditions of process assets, empowering staff to track
instrument health, and then initiate maintenance proactively
to keep operations running smoothly.

Turn enhanced data into operational optimization insights
Control systems regularly use flow, pressure, temperature,level, and other measured values to monitor and control
processes, but they often discard or lack access to status anddiagnostic data. By not using this supplementary information
facilities miss out on opportunities to optimize, simplify, andsafeguard their plant operations.
Instead, if this data can be ingested by intelligent plant
analysis systems, facilities are able to increase their ratio of
proactive to reactive maintenance, reducing unplanned
downtime, and minimizing equipment and human safety
hazards. For example, instead of waiting for an alert indicatinga high-temperature condition, process data can be used toprovide a preemptive notification when conditions are detectedthat would lead to this type of issue if left unmitigated.

Comprehensive insights support development of maintenanceplans to organize shutdowns, and evolve maintenanceprocedures from corrective to predictive. Additional cloudbased tools can be used to generate process optimization
insights, identifying parameter changes and strategy
adjustments that can lead to improved operational efficiency.
Avoiding undesirable conditions
A hazardous waste incineration company leveraged
WirelessHART-enabled instruments (Figure 4) and cloudbased analytics to detect and clear pipe scaling in its flue gas3

denitrification unit. The unit’s heat exchanger experienced
severe scaling, reducing its efficiency, and it required
extensive periods of downtime to clear the clogs.
By installing additional pressure and temperaturetransmitters throughout the unit — and integrating theinstrument data wirelessly with a Fieldgate SWG70 edge
gateway — the company began digitally recording a vast
amount of additional process data, which they passed tocloud-based tools for analysis (Figure 5). Using the process
and diagnostic data, these cloud tools leveraged artificial
intelligence and machine learning to accurately predict pipe
scaling accumulation. Equipped with these insights, plant
personnel made small adjustments to the process, greatly
reducing the rate of scaling.
The company is now expanding their cloud capabilities bypreparing their cloud-based computerized maintenancemanagement system to automatically issue workorders when
the analytics system detects process issues. It will also connect
to the inventory database, keeping tabs on available spareparts, and will digitally issue orders for those in short supply.
Figure 4: A hazardous waste incineration company added multiple
Endress+Hauser pressure and temperature transmitters with SWA50
WirelessHART/Bluetooth communication adapters to detect scaling
in its flue gas denitrification unit.

Comprehensive correlations
For public utilities, an upgrade to digital communications andsmart instrumentation serves to supply edge- or cloud-based
tools with water, air, gas, electricity, and steam consumption

Figure 5: Wireless data transmission and collection at Endress+Hauser’s Fieldgate SWG70 edge gateway eliminates the need for conduits andwires between instruments and host systems.

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data, supporting the creation of correlations with process
inputs and outputs. This helps users understand where theirfacilities are using these resources and guides efforts toreduce waste.

create operational and maintenance insights. Two-way
communication from smart instruments to host systems
provides multivariable process values and extensive
diagnostic information.

In the chemical industry, environmental contaminants areoften a concern, so dedicated systems are installed tomitigate pollutants prior to discharge. These systems areoften controlled separately from manufacturing equipment,
but efficiency and safety can be increased by installing smart
instrumentation at these locations so they can be closely
integrated with the central control system. Wireless digitalcommunication protocols make integration much simpler
than running costly cables, especially over long distances.

Insights derived in this manner help users improve process
efficiency and assist in avoiding unplanned shutdowns byaiding the development of proactive maintenance procedures.
Data can be reviewed locally at a facility, and expanded to thecloud so insights can be accessed remotely by external
support personnel and process experts. This can further
increase an organization’s productivity and response speed
when issues arise.

At facilities with manufacturing machinery, continuous asset
monitoring is critical to detect impending mechanicalequipment failure, so proactive maintenance can beperformed to avoid excessive downtime. Leveraging thehealth monitoring diagnostics of smart equipment, such asactuators, manufacturers can increase productivity andreduce maintenance costs.
Digital advancements
For optimizing plant processes, the implementation ofdigital protocols and smart instrumentation provides
indispensable data for host systems, which can be used toWhether an organization is well along on their digitalization
journey, or just beginning, it is undeniable that industry
reliance on digital data and the IIoT is becoming morepronounced. By deploying network infrastructure and smart
instrumentation throughout their enterprises, companies are
better prepared to continuously optimize their processes andremain competitive in the digital age.
All figures courtesy Endress+Hauser

About the Author
Fabrício de Andrade is an
IIoT Business Development
Manager at Endress+Hauser
Digital Solutions inSwitzerland, where he isresponsible for IIoT in Latin
America, Mexico, Spain andPortugal. He graduated inbusiness management andholds an MBA in Marketingand Digital Business, inaddition to a degree inProcess Automation andTelecommunication. He has
more than 15 years of experience working in big process
automation players in Brazil, Germany and Switzerland.

5WP01200S/24/EN/01.24-00

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